All patient data will be collected on Case Report Form(CRF). All data contained in the CRF and in the QoL questionnaires, will be entered into an electronic database and will be checked in order to assess the plausibility, internal consistencies, errors or missing values. For each missing/loose/illegible/wrong data a request for clarification will be automatically generated by the system; it will be named "Query Form" and will be sent to the investigator for answers. At the end of the validation process, the database will be "frozen" and it will be used for statistical analysis.